TY - JOUR
T1 - Structural evolution of oxygen on the surface of TiAlN: Ab initio molecular dynamics simulations
AU - Guo, Fangyu
AU - Wang, Jianchuan
AU - Du, Yong
AU - Holec, David
AU - Ou, Pengfei
AU - Zhou, Hao
AU - Chen, Li
AU - Kong, Yi
PY - 2018/11/22
Y1 - 2018/11/22
N2 - We have employed ab initio molecular dynamics simulations to study the oxidation behavior of TiAlN hard coatings as a function of Al content and temperature. Results show that for TiAlN with a low Al content (Ti
0.75 Al
0.25 N), Ti atoms can always bond with O atoms, while Al atoms bond with O only at a higher temperature. For Ti
0.5 Al
0.5 N, both Al and Ti can bond with O atoms, irrespective of temperature. Through analyzing the displacement height of O-bonded metal atoms, we suggest that titanium oxide nucleates at the outermost layer of Ti
0.75 Al
0.25 N while the outermost layer after Ti
0.5 Al
0.5 N is exposed to oxygen is aluminum oxide. Our simulation results predict, in agreement with experiment, that Ti
0.5 Al
0.5 N has superior oxidation resistance in comparison with Ti
0.75 Al
0.25 N. This study provides an atomistic insight to the initial stage of the oxidation process, which is else difficult to observe experimentally.
AB - We have employed ab initio molecular dynamics simulations to study the oxidation behavior of TiAlN hard coatings as a function of Al content and temperature. Results show that for TiAlN with a low Al content (Ti
0.75 Al
0.25 N), Ti atoms can always bond with O atoms, while Al atoms bond with O only at a higher temperature. For Ti
0.5 Al
0.5 N, both Al and Ti can bond with O atoms, irrespective of temperature. Through analyzing the displacement height of O-bonded metal atoms, we suggest that titanium oxide nucleates at the outermost layer of Ti
0.75 Al
0.25 N while the outermost layer after Ti
0.5 Al
0.5 N is exposed to oxygen is aluminum oxide. Our simulation results predict, in agreement with experiment, that Ti
0.5 Al
0.5 N has superior oxidation resistance in comparison with Ti
0.75 Al
0.25 N. This study provides an atomistic insight to the initial stage of the oxidation process, which is else difficult to observe experimentally.
UR - http://www.scopus.com/inward/record.url?scp=85056988024&partnerID=8YFLogxK
U2 - 10.1016/j.apsusc.2018.11.158
DO - 10.1016/j.apsusc.2018.11.158
M3 - Article
SN - 0169-4332
VL - 470.2019
SP - 520
EP - 525
JO - Applied surface science
JF - Applied surface science
IS - March
ER -